Simultaneous removal of NO and SO2 by combination of gliding arc–microwave hybrid discharge plasma and metal catalytic mesh (or disk); direct reduction

Plasma-based methods for removing NO and SO2 from flue gases, which are main factors of environmental pollution, have been recognized as promising technologies for application to environmental improvement. In this study, an alternative method for the direct reduction of NO and SO2 is proposed by combining gliding arc–microwave hybrid discharge plasma with metal catalysts. Enhancement of the reduction reaction by catalysts located in the hybrid discharge plasma is reported. Although the metal catalysts sprayed on the aluminum disk and the stainless steel mesh operate for a long time in the stable region of the plasma flame, the change in its surface properties is rarely observed, which suggests the possibility of maintaining the catalytic characteristics. The proposed way provides possibility and effectiveness for combining the gliding arc–microwave hybrid discharge plasma with metal catalysts and the potential in its application for promoting plasma chemical reactions.